WiFi 无法使用，并且出现“未找到 WiFi 适配器”错误。
网络信息脚本的结果：
########## wireless info START ##########
Report from: 01 Sep 2020 14:55 +03 +0300
Booted last: 01 Sep 2020 00:00 +03 +0300
Script from: 22 Oct 2018 03:34 UTC +0000
##### release ###########################
Distributor ID: Ubuntu
Description: Ubuntu 20.04.1 LTS
Release: 20.04
Codename: focal
##### kernel ############################
Linux 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
Parameters: ro, quiet, splash, vt.handoff=7
##### desktop ###########################
Ubuntu
##### lspci #############################
01:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 12)
Subsystem: Acer Incorporated [ALI] RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [1025:0866]
Kernel driver in use: r8169
02:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01)
Subsystem: Lite-On Communications Inc BCM43142 802.11b/g/n [11ad:6645]
Kernel modules: wl
##### lsusb #############################
Bus 001 Device 002: ID 8087:8000 Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 003: ID 04f2:b452 Chicony Electronics Co., Ltd HD WebCam
Bus 002 Device 002: ID 04ca:2009 Lite-On Technology Corp. BCM43142A0
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
##### PCMCIA card info ##################
##### rfkill ############################
0: acer-wireless: Wireless LAN
Soft blocked: no
Hard blocked: no
1: acer-bluetooth: Bluetooth
Soft blocked: yes
Hard blocked: no
6: hci0: Bluetooth
Soft blocked: yes
Hard blocked: no
##### secure boot #######################
SecureBoot enabled
##### lsmod #############################
cfg80211 704512 0
acer_wmi 24576 0
wmi_bmof 16384 0
sparse_keymap 16384 1 acer_wmi
mxm_wmi 16384 1 nouveau
wmi 32768 4 acer_wmi,wmi_bmof,mxm_wmi,nouveau
video 49152 3 acer_wmi,i915,nouveau
##### interfaces ########################
##### ifconfig ##########################
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback <MAC address> brd <MAC address>
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp1s0f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
link/ether <MAC 'enp1s0f1' [IF1]> brd <MAC address>
##### iwconfig ##########################
enp1s0f1 no wireless extensions.
lo no wireless extensions.
##### route #############################
##### resolv.conf #######################
[777 root '/etc/resolv.conf' -> '../run/systemd/resolve/stub-resolv.conf']
nameserver 127.0.0.53
options edns0
##### network managers ##################
Installed:
NetworkManager
Running:
root 702 1 0 Aug31 ? 00:00:01 /usr/sbin/NetworkManager --no-daemon
##### NetworkManager info ###############
GENERAL.DEVICE: enp1s0f1
GENERAL.TYPE: ethernet
GENERAL.NM-TYPE: NMDeviceEthernet
GENERAL.DBUS-PATH: /org/freedesktop/NetworkManager/Devices/2
GENERAL.VENDOR: Realtek Semiconductor Co., Ltd.
GENERAL.PRODUCT: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
GENERAL.DRIVER: r8169
GENERAL.DRIVER-VERSION: --
GENERAL.FIRMWARE-VERSION: --
GENERAL.HWADDR: <MAC 'enp1s0f1' [IF1]>
GENERAL.MTU: 1500
GENERAL.STATE: 20 (unavailable)
GENERAL.REASON: 2 (Device is now managed)
GENERAL.IP4-CONNECTIVITY: 1 (none)
GENERAL.IP6-CONNECTIVITY: 1 (none)
GENERAL.UDI: /sys/devices/pci0000:00/0000:00:1c.0/0000:01:00.1/net/enp1s0f1
GENERAL.IP-IFACE: --
GENERAL.IS-SOFTWARE: no
GENERAL.NM-MANAGED: yes
GENERAL.AUTOCONNECT: yes
GENERAL.FIRMWARE-MISSING: no
GENERAL.NM-PLUGIN-MISSING: no
GENERAL.PHYS-PORT-ID: --
GENERAL.CONNECTION: --
GENERAL.CON-UUID: --
GENERAL.CON-PATH: --
GENERAL.METERED: unknown
CAPABILITIES.CARRIER-DETECT: yes
CAPABILITIES.SPEED: 1000 Mb/s
CAPABILITIES.IS-SOFTWARE: no
CAPABILITIES.SRIOV: no
INTERFACE-FLAGS.UP: yes
INTERFACE-FLAGS.LOWER-UP: no
INTERFACE-FLAGS.CARRIER: no
WIRED-PROPERTIES.CARRIER: off
CONNECTIONS.AVAILABLE-CONNECTION-PATHS: --
##### NetworkManager.state ##############
cat: /var/lib/NetworkManager/NetworkManager.state: Permission denied
##### NetworkManager config #############
[[/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf]]
[connection]
wifi.powersave = 3
[[/etc/NetworkManager/NetworkManager.conf]]
[main]
plugins=ifupdown,keyfile
[ifupdown]
managed=false
[device]
wifi.scan-rand-mac-address=no
[[/usr/lib/NetworkManager/conf.d/10-dns-resolved.conf]]
[main]
dns=systemd-resolved
[[/usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf]]
[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:gsm,except:type:cdma
[[/usr/lib/NetworkManager/conf.d/20-connectivity-ubuntu.conf]]
[connectivity]
uri=http://connectivity-check.ubuntu.com/
[[/usr/lib/NetworkManager/conf.d/no-mac-addr-change.conf]]
[device-mac-addr-change-wifi]
match-device=driver:rtl8723bs,driver:rtl8189es,driver:r8188eu,driver:8188eu,driver:eagle_sdio,driver:wl
wifi.scan-rand-mac-address=no
##### NetworkManager profiles ###########
##### Netplan config ####################
[/etc/netplan/01-network-manager-all.yaml]
network:
version: 2
renderer: NetworkManager
##### iw reg get ########################
Region: Asia/Riyadh (based on set time zone)
global
country 00: DFS-UNSET
(2402 - 2472 @ 40), (N/A, 20), (N/A)
(2457 - 2482 @ 20), (N/A, 20), (N/A), AUTO-BW, PASSIVE-SCAN
(2474 - 2494 @ 20), (N/A, 20), (N/A), NO-OFDM, PASSIVE-SCAN
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW, PASSIVE-SCAN
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW, PASSIVE-SCAN
(5490 - 5730 @ 160), (N/A, 20), (0 ms), DFS, PASSIVE-SCAN
(5735 - 5835 @ 80), (N/A, 20), (N/A), PASSIVE-SCAN
(57240 - 63720 @ 2160), (N/A, 0), (N/A)
##### iwlist channels ###################
enp1s0f1 no frequency information.
lo no frequency information.
##### iwlist scan #######################
enp1s0f1 Interface doesn't support scanning.
lo Interface doesn't support scanning.
##### module infos ######################
[cfg80211]
filename: /lib/modules/5.4.0-42-generic/kernel/net/wireless/cfg80211.ko
description: wireless configuration support
license: GPL
author: Johannes Berg
srcversion: 2369BA84B34843FE73A01F4
depends:
retpoline: Y
intree: Y
name: cfg80211
vermagic: 5.4.0-42-generic SMP mod_unload
sig_id: PKCS#7
signer: Build time autogenerated kernel key
sig_key: 02:B6:04:06:D9:82:F4:38:95:E4:6F:84:9F:1D:B4:8E:C5:85:90:8B
sig_hashalgo: sha512
signature: 11:09:20:94:BE:F4:40:A6:FA:D0:3E:51:A8:D4:D2:61:63:79:98:EB:
10:58:65:0E:8E:46:FF:83:C3:09:4D:0D:4E:43:FF:34:22:F3:75:27:
0C:0C:C2:CC:1D:94:31:F0:20:B9:61:67:C9:7C:B4:64:FD:F6:76:2F:
90:66:77:66:E4:CD:48:E9:0A:AA:2D:4C:AB:65:64:6C:0E:B8:FE:80:
29:21:79:61:2D:DE:8B:C2:7F:A5:6D:DD:B8:22:E7:4C:5E:DB:36:17:
98:BE:79:AC:F2:32:15:A4:1A:A5:F3:7D:53:27:44:66:05:C1:4D:9E:
B4:42:CF:CF:B6:D3:5E:76:51:CD:FE:49:CB:88:40:18:05:12:03:3B:
C7:00:6A:E2:C2:67:CF:BD:42:FF:1D:7A:22:73:6B:13:85:1C:40:E3:
2E:66:00:D2:99:A3:DC:1F:21:AB:2F:E4:DB:02:74:83:5B:6D:B7:AE:
D8:35:05:4D:8F:99:27:08:8D:7A:C8:F3:E8:70:7B:B2:C3:0F:59:B6:
4F:8F:F4:FE:02:1C:10:A5:60:27:F0:B4:9D:49:00:47:55:BB:14:73:
4F:25:B1:41:AC:F3:E7:C7:C9:0E:3A:2A:B1:8E:81:B9:8D:29:C9:4E:
58:BA:82:AC:EB:D2:EA:30:BB:90:F0:72:A4:38:8A:D2:81:65:1B:FB:
D3:D8:C9:F5:41:3F:5B:9F:AB:76:C0:F4:3D:44:C1:B4:1D:7B:75:0B:
C6:70:E0:E9:83:D8:33:A7:FE:DB:A0:B1:97:B1:12:26:F7:22:CB:99:
A8:77:A3:EA:3A:DF:A8:8C:82:64:9F:5B:CD:34:E2:1F:79:09:03:C8:
3B:F5:A7:20:CA:B2:8C:EF:C6:50:1F:A2:1F:11:21:91:50:6E:6F:A9:
89:00:5C:4D:84:9D:07:09:BC:A9:2E:B5:F0:1E:BB:75:D7:8E:9C:20:
8A:6F:40:DD:7E:40:54:38:09:A3:8B:C2:3C:7B:0A:0F:7E:7E:F3:86:
33:CE:FF:D7:54:5F:89:E4:FE:BB:0F:A2:46:65:20:CE:CC:88:5B:53:
CF:C9:AD:14:9C:FD:0C:6C:F2:A6:2E:DF:B0:E5:7D:A5:28:B1:9F:ED:
12:31:4C:BD:DD:15:F3:A3:13:61:5A:FD:51:3C:7B:3F:5B:9F:D5:C9:
74:B4:2B:F3:6D:6B:96:48:06:29:63:50:1C:6A:3F:F8:C5:43:D4:B1:
A6:D8:00:1D:D8:A1:BF:B4:66:05:36:3A:E5:9F:BC:8E:F9:A4:F1:31:
E1:8D:1C:DF:F5:27:19:95:38:73:DE:FF:D1:81:D5:B7:37:D2:B1:81:
F9:0C:71:F5:5C:30:FF:47:DB:F2:A6:7D
parm: bss_entries_limit:limit to number of scan BSS entries (per wiphy, default 1000) (int)
parm: ieee80211_regdom:IEEE 802.11 regulatory domain code (charp)
parm: cfg80211_disable_40mhz_24ghz:Disable 40MHz support in the 2.4GHz band (bool)
##### module parameters #################
[cfg80211]
bss_entries_limit: 1000
cfg80211_disable_40mhz_24ghz: N
ieee80211_regdom: 00
##### /etc/modules ######################
##### modprobe options ##################
[/etc/modprobe.d/amd64-microcode-blacklist.conf]
blacklist microcode
[/etc/modprobe.d/blacklist-ath_pci.conf]
blacklist ath_pci
[/etc/modprobe.d/blacklist-bcm43.conf]
blacklist b43
blacklist b43legacy
blacklist ssb
blacklist bcm43xx
blacklist brcm80211
blacklist brcmfmac
blacklist brcmsmac
blacklist bcma
[/etc/modprobe.d/blacklist.conf]
blacklist evbug
blacklist usbmouse
blacklist usbkbd
blacklist eepro100
blacklist de4x5
blacklist eth1394
blacklist snd_intel8x0m
blacklist snd_aw2
blacklist prism54
blacklist bcm43xx
blacklist garmin_gps
blacklist asus_acpi
blacklist snd_pcsp
blacklist pcspkr
blacklist amd76x_edac
[/etc/modprobe.d/blacklist-rare-network.conf]
alias net-pf-3 off
alias net-pf-6 off
alias net-pf-9 off
alias net-pf-11 off
alias net-pf-12 off
alias net-pf-19 off
alias net-pf-21 off
alias net-pf-36 off
[/etc/modprobe.d/intel-microcode-blacklist.conf]
blacklist microcode
[/etc/modprobe.d/iwlwifi.conf]
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211
##### rc.local ##########################
grep: /etc/rc.local: No such file or directory
##### pm-utils ##########################
##### udev rules ########################
##### dmesg #############################
[ 5426.988330] r8169 0000:01:00.1 enp1s0f1: Link is Down
[ 7457.323889] bluetooth hci0: Direct firmware load for brcm/BCM43142A0-04ca-2009.hcd failed with error -2
[ 7457.323893] Bluetooth: hci0: BCM: Patch brcm/BCM43142A0-04ca-2009.hcd not found
[ 7459.563934] r8169 0000:01:00.1 enp1s0f1: Link is Down
########## wireless info END ############
答案1
请在粘贴时注明：
##### secure boot #######################
SecureBoot enabled
在 Broadcom 驱动程序最多人投票的答案中，它说道：
注意在某些计算机中，在执行命令之前，您需要停用 BIOS 中的安全启动选项。这适用于已安装 bcmwl-kernel-source 但驱动程序尚未运行的情况。您可以像这样重新安装，或者通过转到 BIOS 设置禁用安全启动：
sudo apt-get install --reinstall bcmwl-kernel-source
我建议您通过以太网、网络共享或任何可能的方式连接互联网，然后重新安装可能已预签名的驱动程序版本（如上所述）。如果这没有帮助，请尝试在计算机 EFI/BIOS 中禁用安全启动。
答案2
我必须进入 Bios 并首先禁用安全启动（曾是重置由于某种原因）使用 F10。
那么sudo apt-get install --reinstall bcmwl-kernel-source（就不需要我了）。
Broadcom 开源驱动程序似乎未经签名，因此被 UEFI 安全启动过程阻止。
答案3
@pushStack 的解决方案需要网络连接。我使用这个软件包修复了我的网络连接bcmwl-内核源代码在安装 ISO 中。如果您无法访问互联网，可以参考官方 ubuntu 文档。 https://help.ubuntu.com/community/WifiDocs/Driver/bcm43xx 安装软件包bcmwl-内核源代码从终端（在下面的命令中，安装介质安装在 /cdrom
../pool/restricted/b/bcmwl
cd /cdrom/pool/restricted/b/bcmwl
sudo dpkg -i bcmwl-kernel-source*